Adventure Medical Kits Emergency Blanket is meticulously designed never to fail when you're counting on it with your life. It's made of vacuum-metalized polyethylene, which reflects 90% of your body heat while also offering a number of other important features not found elsewhere. It opens easily and will not shred if nicked or punctured. It's also very quiet and won't crinkle in high winds. Its high-visibility orange exterior also makes it easy for rescuers to find you.